In gas turbine engines, the igniter for the combustion chamber is generally installed by placing it in a mounting boss in a cover or wall of the combustion chamber and attaching a connecter of a power source cable to the mounting boss over the igniter. The cable connector locks the igniter in place and makes an electrical connection between the igniter and the power source. The mounting boss is mounted in a hole in the cover or wall and generally supports the igniter with an ignition tip of the igniter extending into the combustion chamber and a connecting terminal of the igniter extending from the wall or cover to connect to the power cable.
In certain turbine engines, access to the igniter becomes difficult after the engine is assembled. The combustor may be located in a deep part of the engine and other engine components may restrict access to the igniter. This is particularly true of aircraft engines, where physical design limitations demand a tightly packed configuration of the engine components. The installation and removal of igniters in such configurations is difficult, and in certain cases impossible, without a partial disassembly of the engine.
Igniters in turbine engines are subject to extremes of temperature and gaseous environment and require periodic inspection, and frequently require removal and replacement. For igniters in the engine designs which require at least partial disassembling of the engine for access, the amount of time the engine is out of service and the cost of inspection and maintenance are needlessly increased. It is therefore desirable to provide an extender for an ignition plug that facilitates installation of the igniter in a deep or otherwise difficultly accessed engine combustor and allows access to an igniter in an assembled engine for inspection and maintenance.
U.S. Pat. Nos. 3,800,530 to Nash and 4,798,048 to Clements disclose igniter assemblies for augmenter gas turbine engines. These patents disclose devices for extending an igniter into a gas turbine engine augmenter, but not for extending the igniter plug from the engine cover to facilitate installation and removal.
U.S. Pat. No. 4,903,476 to Steber et al. discloses a ball-joint supporter for a gas turbine igniter that permits transverse movement of the igniter electrode tip in response to differential thermal expansion of the combustor casing during operation.
U.S. Pat. No. 4,194,358 to Stenger discloses a double annular combustor having a radially inner pilot stage and radially outer main stage. An elongated igniter tube mounted in the combustor shell extends to the pilot stage but operates conventionally otherwise.
The art does not provide an extender for a gas turbine engine igniter that facilitates the installation and removal of an igniter in an assembled engine.